The present invention relates to a pickup arm device.
The prior art pickup arm devices are in general provided with a locking nut or the like for permitting the replacement of a cartridge so that the reduction in overall effective mass of the arm is difficult and consequently the improvements of desired characteristics cannot be attained. In order to reduce the effective mass of the arm, there has been proposed an arm construction in which a head shell, upon which is removably mounted a cartridge, is formed integral with an arm at the leading end thereof and the other or base end of the arm is connected with a locking nut or the like to a rotary base or the like which is rotatable about both the vertical and horizontal axes. However, after a long period of operation a play is produced at the joint between the arm and rotary bearing so that the arm vibrates at a resonance frequency which adversely affects the faithful reproduction.
If an arm is formed integral with a rotary base in order to overcome the above-described problems, the replacement of the arm becomes almost impossible because various components of an automatic playing mechanism or the like are mounted on the axis of the rotary base.